Types of Planted Aquarium Filters – HOB Filters

by Apr 11, 20216 comments

Now that you know the different and critical types of filtration in a planted aquarium, how it relates to Mother Nature’s natural water filtration systems, and how aquatic plants aid in the water’s filtration in our aquariums, it is now time to discuss all about planted aquarium filters.

Planted aquarium filtration is the lifeline of all the inhabitants in the tank. Aquarium filters remove physical, dissolved chemical wastes and other contaminants from the tank. Without it, you would have to change the water more frequently, and this hobby becomes a chore (you will not be able to enjoy your planted aquarium that way). It simplifies our maintenance and widens the days between water changes.

Furthermore, it affects the health and well-being not only of your faunas but also your plants. Aquarium filters are critical to support life in your tank. As I said before, our planted aquariums are a relatively small and enclosed ecosystem compared to our faunas’ natural environment. We have no running water here, and at the very least, we should replicate their natural environment by using an appropriately sized filter.

 

Table of Contents

Functions of a Planted Aquarium Filter
Types of Planted Aquarium Filters
Power Filters/Hang-on-Back
How does a HOB filter work?
Is there any room for customizations with a HOB?
How do I maintain a HOB filter?
Are there any additional features that I should look out for?
Are there any disadvantages when using a HOB?
Pros
Cons
Stressing This Out Again!
Can We Do Filter Maintenance Along With Water Change?
Conclusion
Closing Remarks

The function of an aquarium filter for our planted aquarium is not limited only to provide filtration.

  • A suitably sized aquarium filter can provide the needed water flow or turbulence to distribute the nutrients and CO2 (if you are injecting CO2, prolonging the CO2 bubbles contact with water so it can be dissolved before it reaches the surface).
  • Not just distributing nutrients and CO2, it provides the water current that some fish loves to swim against. Plants swaying with the gentle water current is a sight to behold.
  • It is a breeding ground for beneficial bacteria to break down harmful Nitrogenous compounds (Ammonia, Nitrites) into less harmful ones (Nitrate).
  • An aquarium filter can also provide the water surface agitation, aerating the water for our faunas and beneficial bacteria’s nitrification activities.
  • It can also prevent the accumulation of wastes, sludge, mulm in the substrate, keeping them suspended/floating so they can be taken in by the filter’s intake.
Mountain River flowing on rocks acting as filters

There are numerous things to consider when buying your planted aquarium filter by providing each filter’s pros and cons. Still, before we get to that and find you the right one (you can even DIY your own filter), you need to familiarize yourself with the different types of filters available in the market. Also, we are on a planted aquarium website. Obviously, we will discuss those popular filters applicable to a planted aquarium.

So Undergravel filters, you are out! Nobody wants to rescape their planted aquariums every 2 to 3 months to clean the detritus that’s been pinned down by this filter. With the advent of aquascaping, that’s the nail in its coffin.

Types of Planted Aquarium Filters

Power Filters/Hang-on-Back

They are also called hang-on-back filters (HOB), and are designed to hang on the back of your aquarium, eing! Power filters are the most commonly used planted aquarium filter because they provide good to excellent mechanical and biological filtration simultaneously. They can also provide the needed water surface agitation for aerating your water.

Front View HOB Filter by Algine Francis de Ramos Philippines

Front View HOB Filter by Algine Francis de Ramos Philippines

A HOB Filter and its Various Filtration Media by Algine Francis de Ramos Philippines

A HOB Filter and its Various Filtration Media by Algine Francis de Ramos Philippines

How does a HOB filter work?

The filtration action is done by sucking the water by a water pump through a siphon tube and then into different mechanical and biological media layers in its filter box. The water is returned to the tank by its return flow.

Is there any room for customizations with a HOB?

You can also customize the media you want to put into the filter box and not necessarily use the included media, which usually contains activated carbons. Chemical filtration is not needed long-term in a planted aquarium, as mentioned and explained in the previous article Types of Planted Aquarium Filtration.

You can also take advantage of a HOB filter’s return flow to prolong the CO2 bubbles’ contact with water by placing your diffuser under it when injecting CO2.

How do I maintain a HOB filter?

They are straightforward to set up and maintain. Please refer to the maintenance manual of your specific HOB filter model. To add to that, do not maintain/clean your filter/media with chlorinated tap water! Always see to it that you clean your filter media using old extracted water from a water change. Tap/chlorinated water can instantly kill the beneficial bacteria you have long-established. Your tank cycling reverts to zero. You will have the agony to repeat it (Hello cloudy water/bacterial bloom!!!).

Squeeze and rinse whatever mechanical media you have with old tank water only from a water change to release all the detritus, muck, organic matters trapped by it. Keep your biological media wet by submerging them, also in collected old tank water. Do not use foams, sponges, brush, even your fingers, or any abrasive products to scrub them (your biological media). Just rinse them with old tank water.

You can put a pre-filter sponge in the HOB intake to prevent baby shrimps/fishes from being sucked. You can then clean your pre-filter sponge/foam without dismantling your HOB filter.

    HOB Filter Providing a Waterfall effect in a Paludarium Aquascaped by Ian Garrido Philippines

    HOB Filter Providing a Waterfall effect in a Paludarium Aquascaped by Ian Garrido Philippines

    Are there any additional features that I should look out for?

    Some other models have a “Rain System” in which the water is trickled down into various mechanical and biological media to exposed the water into as much air as possible to oxygenate the water further. This is for your beneficial bacteria’s more efficient nitrification activities and for your faunas and plants. Some also have an adjustable flow rate and a water surface skimmer. Some HOB models have spray bars for an outtake. This is to solve a HOB limitation to provide only a downward flow by providing a horizontal flow. Improving the circulation of water across the whole tank.

    There are literally thousands of sizes and types/additional features from popular brands that fit almost any aquarium. And because of the low-medium price, HOBs are usually the perfect filters for beginner hobbyists.

      HOB Filter Close Up Aquascaped by Omar Krishnan Afuang Philippines

      HOB Filter Close Up Aquascaped by Omar Krishnan Afuang Philippines

      Are there any disadvantages when using a HOB?

      However, HOB filters may not work, or you need to DIY/customize them to make them fit in a braced tank. You may also need to use two HOBs as your main filtration in larger tanks above 20 gallons, or you can use a HOB along with a Canister filter to supplement your filtration. But there are larger HOBs that can support tanks up to 30 gallons.

      To summarize, here are the pros and cons of a HOB filter:

      Pros

      • Easy maintenance
      • Great entry-level option
      • Can be an effective filtration for small to medium tanks (nano tanks, 10, 15, up to 20 gallons tank)
      • Can provide 3 types of filtration – most importantly, mechanical and biological
      • Easy to set-up
      • It takes up less space – you can conceal the tube with your plants and hardscape, not to ruin the look of your scape.
      • Extensive additional features from different brands – from adjustable flow, Wet/Dry Trickle-like features (Rain System), you can put pre-filters, different sizes to choose from, silent-types, more room for your media, etc., there are no compromises here considering the size of the tank mentioned above, and you have a lot of choices.

        HOB Filter Nano Tank Aquascaped by Bet Señeres-Layog Villareal Philippines

        HOB Filter Nano Tank Aquascaped by Bet Señeres-Layog Villareal Philippines

        Cons

        • If you have a Euro braced tank, HOB filters may not fit, or you have to DIY/customize to make it fit and secure.
        • The return flow is downwards only – this means that the intake and return flow are close in proximity. The circulation of filtered water across the whole tank is somewhat inefficient for medium tanks. But some HOBs have spray outtake features improving the water circulation across the whole tank.
        • If you have a medium to a large tank, 30 gallons and up, you will need two HOBs to make the filtration efficient. Not a disadvantage per se, it’s the wrong choice of filter, and you could have chosen a Canister filter anyway for larger tanks.
        HOB Filter Aquascaped by Omar Krishnan Afuang Philippines

        HOB Filter Aquascaped by Omar Krishnan Afuang Philippines

        Stressing This Out Again!

        Whichever filter you had chosen from the list above, do not maintain/clean your filter/media with chlorinated tap water! Always see to it that you clean your filter media using old extracted water from a water change or a water source known to have no chlorine. Tap/chlorinated water can instantly kill the beneficial bacteria you have long-established. Your tank cycling reverts to zero. You will have the agony to repeat it (Hello cloudy water/bacterial bloom!!!).

        Squeeze and rinse whatever mechanical media you have with old tank water only from a water change to release all the detritus, muck, organic matters trapped by it. Keep your biological media wet by submerging them, also in collected old tank water. Do not use foams, sponges, brushes, even your fingers, or any abrasive products to scrub them (your biological media). Just rinse them with old tank water.

        HOB Filter Aquascaped by John Michael Limjoco Philippines

        Dual HOB Filter Aquascaped by John Michael Limjoco Philippines

        HOB Filter Aquascaped by Marc Villanueva Philippines

        HOB Filter Aquascaped by Marc Villanueva Philippines

        Can We Do Filter Maintenance Along With Water Change?

        Contrary to popular practice, some hobbyists will say that you cannot perform filter maintenance along with your water change schedule. This happened to me on some occasions due to scheduling conflicts.

        While the most obvious disadvantage is you have many tasks to do, you can still do both subsequently in just under an hour. One advantage of this is you can use the old tank water extracted from your water change to rinse/clean your filter, filter media, and its accessories/parts, not compromising your good bacteria.

        Just keep in mind that you keep your filter media wet and submerge using old tank water extracted during your water change. Wash and rinse your mechanical media (foams, filter floss, polyester pillow stuffings, etc.) with old tank water.

        Clean your filter and hoses, in my case, my Canister filter with the same old tank water. Arrange your filter media back and quickly to avoid drying them out.

        Let me share with you my routine when I stumbled with this situation:

        1. Turn off your filter, surface skimmer, and pumps if there are any.

        Front View During Water Change 25 %

        Front View During Water Change After Siphoning 25 %

        Top View During Water Change 25 %

        Top View During Water Change After Siphoning 25 %

        2. Perform your water siphoning according to how much percentage of water volume you want to change. While you are at it, vacuum your substrate as well. You may want to vacuum your mosses as well. You will be surprised how much debris, detritus, etc. are in your mosses (try to disturb the water around them, and you will see what I mean). They act as mechanical filters for small to medium particulates, dead organic matter, fish food, etc., in our planted aquariums.

        3. Put the extracted water into pails or a big water basin.

        Siphoning my Substrate and Carpet Plants

        Siphoning my Substrate and Carpet Plants

        Trimming my Mosses while siphoning them

        Trimming my Mosses while siphoning them

        Extracted water from a Water Change into a Basin

        Extracted water from a Water Change into a Basin

        4. I don’t fill up the tank yet with new water usually, but I turn on my aquarium fan to provide water surface agitation for my faunas. Depending on your filter type, this may take considerably more time compared to just a water change schedule. You can also choose to fill up your tank with new chlorine-free water. It is totally up to you.

        5. Next, dismantle your filter. Put your biological filter media and submerged them in the extracted water earlier.

        6. Wash, squeeze, and rinse your mechanical media (foams, filter floss, polyester pillow stuffings, etc.) with old tank water. Do this in a separate and smaller basin to avoid clouding the water in the big basin where your biological media are and avoid the nasties getting into your biological media.

        7. Clean the inside walls of your filter and hoses with the same old tank water. For hoses, you can use hose brush cleaners.

        8. Assemble your filter media back into the filter quickly to avoid drying them out.

        Keeping my Biological media wet using old tank water during water change

        Keeping my Mechanical and Biological media wet using old tank water during a water change

        My Filter Tubings starting to get dirty

        My Filter Tubings starting to get dirty

        My Tube Cleaning Brush

        My Tube Cleaning Brush to clean my filter hoses

        After cleaning the inside walls of my Canister Filter

        After cleaning the inside walls of my Canister Filter

        9. In my case, I have a canister filter. I pour water from my tank, not from the water basin, to submerge my filter media. Set it aside for now. If you have a HOB filter, Overhead filter, sponge filter, or internal filter, etc., you can already set them up in the tank.

        10. I fill my tank with new water. I remineralize it beforehand because I am using RO/DI water. Skip this if you’d fill up your tank in step # 4.

        11. Next is to set up my Canister filter in its original position, insert the hoses, and then position the intake and outtake.

        12. Turn on the filter, surface skimmer, and pumps if there’s any, and enjoy your hard work.

        Assembling My Canister Filter and its Media Trays

        Assembling My Canister Filter and its Media Trays

        After Positioning My Canister Filter and its Hoses

        After Positioning My Canister Filter and its Hoses

        Conclusion

        In this article, we concluded the importance of a carefully chosen planted aquarium filter and how critical it is to support life in our tanks. It can distribute nutrients and CO2 across the whole tank and provides the water current that fish loves to swim against. It can also be a breeding ground for beneficial bacteria, provides the needed water surface agitation, oxygenating the water for our faunas, and nitrification activities.

        First on the type of filter is the HOB filter. It is designed to hang on the back of an aquarium and can provide good to excellent mechanical and biological filtration for medium to small tanks.

        The HOB filter is very straightforward to maintain. There are thousands of sizes and types/additional features from popular brands that fit almost any aquarium. And because of the low-medium price, HOBs are usually the perfect filters for beginner hobbyists.

        We also provided the numerous pros and cons of the HOB filter. Few models are designed for large tanks as well as providing only a downward flow in the outtake. You are somewhat limited, too, to how much media you can put into it. But for small to medium tanks, the pros outweighs its cons.

        Finally, regardless of your chosen filter, we discussed how you can maintain your filter without compromising your beneficial bacteria and if we can perform filter maintenance along with water change.

        Closing Remarks

        I hope you enjoyed this article. If you have additional questions or want to share your experiences with the Hang on Back Filters, you used, please leave a comment below.

        Next, we will be discussing the Internal Filters – a filter that is situated inside your planted aquarium.

        6 Comments

        1. Robert

          Hello! It seems like the hang-on-back filters (HOB filters) would be most beneficial for small and medium-sized tanks since they’re easier to clean and maintain. I don’t have a lot of experience with tanks and filters, but I understand that mimicking natural habitat is critical. You mentioned that owners shouldn’t use chlorinated tap water. When you’re first filling up your tank, what water would you use? Would it be best to get gallons of water from a store that does not have chlorine? On second thought, is there a filter that could take that chlorine out? Those would be useful features for a filter. The information you provided is useful! I appreciated your article.

          Reply
          • Lemuel Sacop

            Hello Robert and thank you for visiting my website. With regards to your question, this is the link when I discussed the safe water sources that we can use for our planted aquariums.

            https://allaboutplantedaquariums.com/safe-water-sources-for-our-planted-aquarium/

            You can still use tap water, which is known to be treated with Chlorine or Chloramine, you can also use water conditioner products like Seachem Prime or API Water conditioner to remove the chlorine. Or you can just stock the tap water for a few days so that the chlorine will evaporate.

            Each water sources have pros and cons and I think this article will help you to choose the best water source if ever you want to try this hobby, and may turn to passion, at your very own home.

            Reply
        2. Rob Corbett

          Really interesting post. I used to have a large fish tank and I loved the idea of having plants in it but I aleways figured it was too big of a chore, from the looks of the photos in your post I should have given it a try as they are beautiful and add a nice look to the aquarium.

          I have used hob filters before and had pretty good luck with them. I always went a little bit larger then I thought was required just to make sure they were keeping the tank water nice and clean. When done right it really does spread out the time between water changes and allows you to enjoy your tank more and not make it into a chore as you said. When I was a kid my Father had a very large fish tank and he would get us kids involved in cleaning it and it was very much of a chore, no fun at all. lol

          Thanks for the information.

          Reply
          • Lemuel Sacop

            Hello Rob! Thank you for sharing your experiences with a HOB filter. I hope, in some way or two, I was able to help you in your decision to try a planted aquariums as well at your home.

            Reply
        3. Ivan

          Hey, thanks for sharing this post. It seems like hong on back (HOB) type of aquarium filters have a lot of pros. I like the fact that they are easy to install and maintain. The only downside, in my opinion, is that you have to actually use two of these filters, am I right? I don’t really have any experience with aquarium filters and aquariums in general. This is all new to me. But I like your site here. You have helped me a lot to understand ins and outs. A have a question. Are there any other types of filters that you would recommend in this post? Initially, I thought that you will be talking about a wide variety. As I said, I like the idea behind HOB filters, but I would also like to know what alternatives can you offer. I hope this is not a bother. Thanks in advance!

          Reply
        4. Jason

          Cool site Lemuel – the green background really pops out. We have a HOB filter on our tank but have typically had challenges with it. Cleaning might be part of it but I think we have the wrong size (too small) so some of the plant life dies. Will have to check it out more so thanks for the suggestions.

          All the best – Jason.

          Reply

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